1. Field of the Invention
The present invention relates to a door plate driving mechanism of an air conditioning system for an automobile, and more particularly, the present invention relates to a door plate driving mechanism for an air conditioning system of an automobile, which has an improved structure for accomplishing selectively interlocked operations of a plurality of door plates which are rotatably secured to an air conditioning case and disposed in an air conditioning path to control air flow into a passenger compartment.
2. Description of the Prior Art
Conventionally, an air conditioning system for an automobile has an air conditioning case which is disposed behind an engine room. The air conditioning case is made of injection molded plastic, etc. and defines a part of an air conditioning path. In the air conditioning case, there are disposed a plurality of operating elements including a blower fan, an evaporator and a heater. A plurality of door plates are also disposed in the air conditioning case to selectively control opening and closing of a plurality of conduits which serve to supply air conditioned by the plurality of operating elements to various regions of a passenger compartment.
Each of the plurality of door plates has a rectangular plate-shaped configuration and is rotatably secured to the air conditioning case by a hinge shaft so that it can open and close a corresponding conduit. A plurality of driving levers are securely fixed to one end of the hinge shafts, respectively, which project out of the air conditioning case. The driving levers having various configurations and sizes, respectively, are rotated by a vacuum actuator, a motor actuator or the like. When driving levers selected relying upon an air conditioning mode are rotated by the actuator, corresponding door plates are also integrally rotated therewith to open or close corresponding conduits.
It is preferred that the plurality of door plates disposed in the air conditioning path are driven by one actuating means such as the motor actuator, to simplify the structure and reduce manufacturing cost of the air conditioning system. In this connection, various door plate driving mechanisms for selectively driving the plurality of door plates using one actuating means, are disclosed in the art.
In an exemplary door plate driving mechanism of the prior art, a plurality of driving levers are securely fixed to hinge shafts of a plurality of door plates, respectively. Each of the driving levers is formed with an upright pin, and a driving plate is arranged above the driving levers. The driving plate is formed with a plurality of guide grooves into which the upright pins of the driving levers are inserted, respectively. The driving plate is connected to an actuator means, and the plurality of guide grooves incorporate pivoting routes of the plurality of driving levers, respectively. If the driving plate is rotated by the actuator means, the driving levers are rotated around the hinge shafts, respectively, to control driving modes of the plurality of door plates.
In another door plate driving mechanism of the prior art, a plurality of driving levers securely fixed to hinge shafts of a plurality of door plates, respectively, are connected through a plurality of articulated links to a driving plate to drive the plurality of door plates in a selectively interlocked manner relying upon an air conditioning mode.
However, the door plate driving mechanisms of the prior art have deficiencies as described below:
(1) Since the structure of the door driving mechanism of the prior art has a number of the components, manufacturing cost is increased.
(2) The hinge shafts of the respective door plates, driving levers securely fixed to the hinge shafts, and driving plate connected directly or via the plurality of articulated links to the driving levers have kinematic limits in their operations, whereby noise is generated. Further, geometrical critical points on which operations of the components cannot be properly controlled, exist in the door plate driving mechanism.
(3) Since the plurality of driving levers are simultaneously operated, driving force generated by the actuator must be fairly large.
(4) Since the plurality of components are interconnected one to another, tolerances in manufacturing the components and allowances in assembling the components become smaller. For this reason, assembling time is lengthened, assembling errors occur frequently, and difficulties arise in A/S.
Hereinafter, a door plate driving mechanism according to the prior art will be described in detail with reference to FIGS. 1 through 5.
First, referring to FIG. 1, there is shown a cross-sectional view schematically illustrating a construction of an air conditioning system for an automobile. An air conditioning path 1 defined by a plurality of air conditioning cases 10 includes a blower fan 2, an evaporator 3, a heater 4 and a plurality of door plates as being operating doors. A heater door plate HT for controlling discharge of air which is passed through the heater 4, a vent door plate VT for controlling discharge of air toward a driver seat, and a defrost door plate DF opened under a defrosting mode, are integrally assembled onto a selected plane of one air conditioning case 10. The drawing reference numeral 5 represents a temperature-adjusting door plate.
Accordingly, the heater door plate HT, vent door plate VT and defrost door plate DF which constitute the plurality of door plates, are rotatably secured to the air conditioning case by hinge shafts, respectively. The air conditioning case is made of injection molded plastic and has a box-shaped configuration. While the plurality of door plates are driven by a vacuum actuator or a motor actuator, it is important that the plurality of door plates are designed such that they are smoothly driven in selectively interlocked manners by an actuator having a capacity as low as possible. This is because the air conditioning case 10 is not large in its size and the number of components must be as small as possible in view of manufacturing cost and controllability thereof.
For this purpose, door plate driving mechanisms for driving the plurality of door plates using one actuating means, are disclosed in the art. An example of the door plate driving mechanisms is illustrated in FIGS. 2 through 5. Referring to FIG. 2, there is shown a perspective view illustrating an air conditioning case on which a door plate driving mechanism of the prior art is mounted. FIG. 3A is a perspective view showing an independent appearance of a driving plate used in the door plate driving mechanism of FIG. 2.
The plurality of door plates are selectively operated while they are interlocked with a driving plate. In one example, driving modes of each door plate are given as described in Table 1, relying upon an air conditioning mode.
To be operated under the exemplary driving modes given in Table 1, the vent door plate VT, defrost door plate DF and heater door plate HT are rotatably secured to the air conditioning case 10 by the respective hinge shafts 11, 12 and 13. Driving levers 21, 22 and 23 are securely fixed to one end of the hinge shafts 11, 12 and 13, respectively, which project out of the air conditioning case 10.
Three intermediate levers 31, 32 and 33 are also rotatably secured to the plane of the air conditioning case 10 adjacent to the driving levers 21, 22 and 23, respectively. The intermediate levers 31, 32 and 33 are meshed with the driving levers 21, 22 and 23, respectively, and are formed with three upright pins 41, 42 and 43, respectively. By the fact that the upright engaging pins 41, 42 and 43 are inserted into guide grooves 51, 52 and 53, respectively, which are formed in the driving plate 50, the intermediate levers 31, 32 and 33 are connected to the driving plate 50 so that they can rotate by the rotation of the driving plate 50. The driving plate 50 is connected by a shaft to the actuator 55 such as the vacuum actuator, motor actuator, or the like, to be driven thereby.
The respective guide grooves 51, 52 and 53 formed in the driving plate 50, include a plurality of arc-shaped portions communicated one to another. The arc-shaped portions of the respective guide grooves 51, 52 and 53 are geometrically designed such that when the driving plate 50 is rotated by the actuator 55, it operates the vent door plate VT, defrost door plate DF and heater door plate HT under the driving modes as given in the Table 1.
An exemplary driving mode is shown in FIG. 3B which is a schematic plan view for explaining operations of the door plate driving mechanism according to the prior art. As described above, when the driving plate 50 which is formed with the guide grooves 51, 52 and 53 each including the plurality of arc-shaped portions is rotated by the actuator 55, the door plates VT, DF and HT are selectively operated under a plurality of air conditioning modes including VENT, BI-LEVEL, HTR, HTR/DEF, and DEF modes (Details of the arc-shaped portions, and positions of the intermediate levers 31, 32 and 33 relative to the driving plate 50 will not be described).
Referring to FIG. 4, there is shown a perspective view similar to FIG. 2, for illustrating a state in which the driving plate is removed from the door plate driving mechanism.
In the door plate driving mechanism of the prior art, constructed as mentioned above, a number of components must be assembled within a narrow allowance. If a size of an air conditioning case is varied in accordance with a change in air conditioning capacity, geometrical configurations of the plurality of guide grooves must be newly designed on a new driving plate. However, since the design of the geometrical configurations of the guide grooves are performed on a trial and error basis, a great deal of effort and time is required.
Referring to FIG. 5, there is shown a perspective view illustrating an air conditioning case on which another door plate driving mechanism of the prior art is mounted.
For driving the heater door plate HT, vent door plate VT and defrost door plate DF which constitute the plurality of door plates, a plurality of links L1, L2, L3, L4, L5 and L6 are provided to connect the door plates HT, VT and DF to a driving plate. However, this door plate driving mechanism still has the above-stated problems of the prior art.
Hence, the door plate driving mechanisms of the prior art have problems in that its structure is complicated, its operation reliability is reduced, a break-down may be caused by kinematic limits due to assembling allowances, and manufacturing cost is elevated.
Therefore, a demand for a door plate driving mechanism which has improved operation reliability and is capable of eliminating worry about break-down due to assembling allowances, is increasing in the art.
Accordingly, the present invention has been made in an effort to solve the problems occurring in the prior art, and an object of the present invention is to provide a door plate driving mechanism of an air conditioning system for an automobile, which has a simple structure to decrease the number of components and reduce manufacturing cost while enhancing operational reliability.
In order to achieve the above object, according to one aspect of the present invention, there is provided a mechanism for driving a plurality of door plates of an air conditioning system for an automobile, the door plates being rotatably mounted to an air conditioning case for being operated under a multitude of air conditioning modes, the air conditioning case defining a part of an air conditioning path, the mechanism comprising: actuator means for generating a rotating force to operate at least one door plate under a selected air conditioning mode, the actuator means having an output shaft; a main gear plate secured to the output shaft of the actuator means and having a first driving section and a first mesh limiting section which are integrally stacked with each other, the first driving section having a plurality of first toothed portions for transferring the rotating force, the first mesh limiting section having a predetermined mesh limiting construction for performing the selected air conditioning mode; and a plurality of driving levers fixed to the plurality of door plates, respectively, each of the driving levers having a second driving section and a second mesh limiting section which are integrally stacked with each other, the second driving section having a second toothed portion which is capable of being meshed with at least one of the plurality of first toothed portions of the main gear plate for driving at least one door plate under the selected air conditioning mode, the second mesh limiting section cooperating with the first mesh limiting section for effecting non-meshed rotation of the main gear plate.
According to another aspect of the present invention, there is provided a mechanism for driving a plurality of door plates of an air conditioning system for an automobile, the door plates being rotatably mounted to an air conditioning case for being operated under a multitude of air conditioning modes, the air conditioning case defining a part of an air conditioning path, the mechanism comprising: actuator for generating a rotating force, the actuator having an output shaft; a main gear plate secured to the output shaft of the actuator for being integrally rotated therewith and having a plurality of first toothed portions and a plurality of non-meshed rotation guide arms, the first toothed portions being formed on a circumferential outer surface of the main gear plate such that they are circumferentially spaced apart one from another, the non-meshed rotation guide arms being formed on one surface of the main gear plate such that they are circumferentially spaced apart one from another and extend radially; and a plurality of driving levers fixed to the plurality of door plates, respectively, each of the plurality of driving levers having a second toothed portion which is capable of being meshed with at least one of the plurality of first toothed portions of the main gear plate and being able to have a rounded guide portion on which at least one of the plurality of non-meshed rotation guide arms can slide to effect non-meshed rotation of the main gear plate thereby to operate at least one door plate under a selected air conditioning mode.
According to still another aspect of the present invention, there is provided a door plate driving mechanism of an air conditioning system for an automobile, comprising: a heater door plate, a vent door plate and a defrost door plate disposed on the same plane of an air conditioning case for being operated under a multitude of air conditioning modes, the air conditioning case defining a part of an air conditioning path; first through third driving levers secured to hinge shafts of the heater door plate, vent door plate and defrost door plate for driving them while being integrally rotated therewith, respectively, each of the first through third driving levers having teeth; a main gear plate for selectively rotating at least one of the first through third driving levers while being meshed with the teeth of the first through third driving levers, relying upon a selected air conditioning mode; and mesh limiting means provided to the first through third driving levers and the main gear plate for selectively restraining the teeth of the first through third driving levers from being meshed with the main gear plate while the main gear plate is rotated, relying upon the selected air conditioning mode.
The first through third driving levers have sector gear-shaped configurations which have predetermined radii of curvature from centers of the hinge shafts and predetermined central angles.
The mesh limiting means provided to the first and second driving levers comprise a plurality of guide members which are integrally formed with the first and second driving levers, respectively, each of the guide members having a rib section and a guide section, the rib section having a plate-shaped configuration and extending radially, the guide section being fastened to one end of the rib section and having a rounded guide face of a predetermined radius of curvature from a center of the main gear plate.
The main gear plate has a disk-shaped configuration, and includes a plurality of operating areas over which teeth are formed on a circumferential outer surface thereof and a plurality of non-operating areas over which no teeth are formed on the circumferential outer surface thereof.
The mesh limiting means provided to the main gear plate having the disk-shaped configuration and including the plurality of operating areas over which teeth are formed and the plurality of non-operating areas over which no teeth are formed, comprises a plurality of non-meshed rotation guide arms which are integrally formed on a one surface of the main gear plate and have predetermined radial lengths from the center of the main gear plate, the plurality of non-meshed rotation guide arms forming a plurality of predetermined controlling angles each of which is defined between two adjacent non-meshed rotation guide arms and having one end which can slide on the rounded guide faces of the first through third driving levers, respectively.
The predetermined radii of curvature of the rounded guide faces of the first and second driving levers are substantially the same with the predetermined radial lengths of the non-meshed rotation guide arms which correspond to the first and second driving levers, respectively.
The door plate driving mechanism further comprises a reverse gear plate for reversely rotating the heater door plate, the reverse gear plate having teeth which are formed on an entire circumferential outer surface thereof.
A selective operation of the heater door plate, vent door plate and defrost door plate relying upon the selected air conditioning mode is implemented by selective meshing between the teeth formed on the circumferential outer surface of the main gear plate over the plurality of operating areas and the teeth formed on the first through third driving levers, and by selective sliding engagement between the one ends of the plurality of non-meshed rotation guide arms and the rounded guide faces of the first through third driving levers.